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Welcome to the Webinar
December 13, 2011
Updating Local Codes to Cultivate
Green Infrastructure and Foster
Sustainable Stormwater Management
The webinar will begin at 1:00 EST
Updating Local Codes to Cultivate
Green Infrastructure and Foster
Sustainable Stormwater
Management
Tanner Springs Park, Portland, OR
A Few Things Worth Mentioning
• Your phone or microphone is on mute. This will
minimize background noise during the webinar.
• We are interested in your questions and
comments. Please Send your questions to the
moderator via the „Question‟ box in the
GoToWebinar dock on the right side of your
screen.
– The moderator will pose the questions
submitted to the speakers.
• This webinar is being recorded. We are looking
into how we can post the webinar with audio, and
just the slides, for later viewing.
• We expect the webinar to last 2 hours.
The Fine Print
This presentation has been organized by the
U.S. Environmental Protection Agency working
with several partners. The presentations today
do not constitute EPA policy. Mention of trade
names or commercial products does not
constitute endorsement or recommendation for
use. Links to non-EPA web sites do not imply
any official EPA endorsement of, or a
responsibility for the opinions, ideas, or products
presented at those locations or guarantee the
validity of the information provided.
Agenda
• Why Green Infrastructure? Regulatory Drivers
and Watershed Approaches
• The Role of Codes and Ordinances
• Code and Ordinance Reviews: Case Studies
and Findings
• Cleveland Heights, Ohio‟s Sustainability Audit
of Codes and Ordinances
• Top Ten Things to Search and Replace in Your
Plans and Codes: Common Problems and
Tested Solutions
• Wrap-up and Questions
Stormwater Runoff from Urban and Suburban Areas
• In urban areas runoff is typically collected in sewers and then discharged via pipes or ditches (so it is a “point source”)
• Testing has shown there can be significant amounts of pollutants in stormwater
• Therefore, U.S. EPA and State agencies regulate stormwater discharges under the Clean Water Act
Stormwater Discharges
Under the Clean Water Act
• EPA and the State focus on 3 types of storm water sources: Municipal storm sewer systems
Factories, Power Plants
Construction Sites
Municipal Separate
Storm Sewer Systems (MS4s) MS4 Six Minimum Measures
1. Public Education and Outreach
2. Public Involvement and
Participation
3. Illicit Discharge Detection and
Elimination
4. Construction Site Control
Runoff
5. Post-Construction Stormwater Management
for New and Re-development
6. Pollution Prevention/Good Housekeeping
for Municipal Operations
MS4 Stormwater Requirements
Illicit Discharge Detection and Elimination
• An Illicit Discharge is a release of non-
stormwater flows to a storm sewer system • Such as a car wash or laundromat
• MS4 communities must develop, implement
and enforce a program to detect and
eliminate illicit discharges
• The community must adopt and implement
“An ordinance or other regulatory
mechanism to prevent and eliminate illicit
discharges and connections to the MS4. “
Illicit Discharge Detection and Elimination
At a minimum, the ordinance or other
regulatory mechanism shall:
• Prohibit the discharge, spilling or
dumping of non-storm water
substances or materials into waters of
the state or the MS4
• Establish inspection and enforcement
authority
MS4 Stormwater Requirements Construction Site Storm Water Runoff Control • Each permittee shall develop, implement and enforce
a program to reduce the discharge of sediment and
construction materials from construction sites
• The program must include: “An ordinance or
other regulatory mechanism to require
erosion and sediment control at construction
sites and establish sanctions to ensure
compliance” • The ordinance must include erosion and sediment
control criteria, standards and specifications
equivalent to those approved by the DNR and
performance standards at least as stringent as NR
151.11 and 151.23
MS4 Stormwater Requirements
Post-Construction Stormwater Management • Communities must develop, implement and enforce a
program to require control of the quality of discharges
from areas of new development and redevelopment,
after construction is completed
• The program must include an ordinance (or other
regulatory mechanism)
• The ordinance must establish/include design criteria,
standards, and specifications equivalent to State
standards
• Must also include post-construction performance
standards at least as stringent as NR 151.12 and
151.24
Many MS4s Implement Post-Construction Ordinance Provisions to Regulate Discharge Volumes
Setting standards for the volume of runoff from new development sites and redevelopment sites
is one of the focus areas for EPA‟s NPDES Stormwater Rulemaking
• Localized Flooding
• Protect Water Quality
Relationships Between Land Use
and Water Resources
60% 0-10%
Development Increases Run-off NEMO
Increased Run-off due to Impervious Surfaces
Roads
Parking
Buildings
Sidewalks
Driveways
Center for Watershed Protection
~10% Impervious Surfaces
As a Watershed
Develops, there
is More and
More Impervious
Cover (and as a
result, more and
more runoff)
Center for Watershed Protection
~ 75% Impervious Surfaces
Center for Watershed Protection
Q
T
Developed Condition, Conventional CN
(Higher Peak, More Volume, and Earlier Peak Time)
Predevelopment Condition
Increased Run-off Changes Stream Flow Characteristics
Low Impact Development Center
• Stream widening and erosion
• Decreased channel stability
• Reduced fish passage
• Loss of pool-riffle structure
• Lower summer base flows
• Loss of riparian tree canopy • Temperature impacts
• Decreased substrate quality • Embeddedness (fine sediments
become embedded into the coarse substrate)
Effects of Higher Flow Volumes
and Higher Flow Velocities…
In watersheds with
less than 5%
impervious cover,
streams are typically
stable and pristine,
maintaining good
pool and riffle
structure, a large,
wetted perimeter,
even during low
flow, and a good
riparian canopy
coverage.
Center for Watershed Protection
At 10% impervious
cover, the stream is
slightly more visibly
impacted. The
stream shown here
has approximately
doubled its original
size, tree roots are
exposed, and the
pool and riffle
structure seen in
sensitive streams is
lost.
Center for Watershed Protection
Active erosion
becomes much more
evident at 20%
impervious cover
with decreased
substrate quality due
to more material
"flushing" through
the system.
Center for Watershed Protection
Stream Channel Erosion
Increased quantity
Decreased quality
Nutrients
Pathogens
Sediment
Toxic Contaminants
Oil and Grease
Thermal Stress
Pollutants in Stormwater Discharges
NEMO
Center for Watershed Protection
Stormwater Volumes and Pollutant Loads
Result in Water Quality Degradation
Existing Programs/Requirements to Address
Stormwater Discharge Volumes
Wisconsin NR 151
• NR151 Performance standards include requirements for total suspended solids, peak flow, infiltration
• Infiltration. This performance standard requires that a portion of the runoff volume be infiltrated:
– Residential – 90 percent of pre-development infiltration volume
– Non-residential – 60 percent of predevelopment infiltration volume
• To protect groundwater, the WI standards identify areas where infiltration is discouraged
• This post-construction program reduces stormwater discharge volumes
New Jersey
The New Jersey Stormwater Management Rules
require that a “major development” project must
comply with one of the following groundwater
recharge requirements:
Demonstrate through hydrologic and hydraulic
analysis that the site and its stormwater
management measures maintain 100 percent
of the average annual preconstruction
groundwater recharge volume for the site; or
Demonstrate through hydrologic and hydraulic
analysis that the increase of stormwater runoff
volume from pre-construction to post-
construction for the 2-year storm is infiltrated
West Virginia MS4 Permit
Municipalities must implement a program to
protect water resources by requiring all new
and redevelopment projects to control
stormwater discharge rates, volumes,
velocities, durations and temperatures
The first 1 inch of rainfall must be 100%
managed with no discharge to surface
waters
Runoff volume reduction can be achieved by
using green infrastructure
West Virginia – Incentives for
Sustainable Development Practices
A credit of 0.2 inches from the one inch runoff
reduction standard may be applied to any of the
following types of development:
• Redevelopment
• Brownfield redevelopment
• High density (>7 units per acre)
• Vertical Density (Floor to Area Ratio of 2 or
>18 units per acre)
• Mixed use and Transit Oriented Development
(within ½ mile of transit) Reductions are additive up to a maximum reduction of 0.75 inches for a
project that meets four or more criteria
What Measures Could Be Implemented to
Reduce Stormwater Discharges and CSOs?
Green infrastructure practices to manage
stormwater
• Increase Infiltration
• Increase Evapotranspiration
• Harvest and Re-use Stormwater
• Reduce Volume of Runoff
Maplewood, MN
Infiltration Practices
Rain Gardens
Burnsville, MN Rain Gardens Throughout
a Neighborhood
drain
Parking Lots
Not so good
Good – Run-off from the parking lot can
be absorbed by the plants and soil
Center for Watershed Protection
H.B.Fuller Company Parking Lot (MN)
• Reduced storm
water discharges
by 73%
• Reduced sediment
discharge by 94%
• Reduced
phosphorus
loading by 70%
NEMO
Permeable Pavement Parking
Morton Arboretum, Lisle, IL
Fat
Street
Center for Watershed Protection
Skinny
Street
Street
Widths
Low Impact Development Center
Seattle Street - Before
Street Retrofits – Narrower Streets + Swales
Seattle Street – After
Seattle street retrofit
monitoring results
for two years:
98-99%
reduction in
total runoff
volume
Michigan Avenue, Lansing, MI
State
Capitol
Michigan Avenue TetraTech and C2AE
Before
Michigan
Avenue
4 city blocks, both
sides
Typical garden, no
overflow for 1-inch
event
600 block north side,
no overflow for 4.1-
inches (25-year event)
$122/square foot TetraTech
Chicago City Hall 20,300 sf intensive green roof with 20,000
plants of more than 100 native species
Installed in 2000
Decreases air and roof surface temperatures
Retains 75% of a one-inch rainfall event
Provides habitat
Green Roofs
Extensive Green Roof Light and Relatively Inexpensive
Highland Gardens, Milwaukee, WI
Storing and Reusing Rainwater
Cisterns
Costs Green vs. Grey Infrastructure
Project Conventional vault
cost estimate* Rain garden cost
Bloedel Donovan
Park parking lot
(4400 ft3 wet vault) $52,800 $12,800
City Hall parking
lot (2300 ft3 wet
vault) $27,600 $5,600
* City of Bellingham‟s estimate using approximate cost of $12.00/ft3 for an in-ground storage and treatment device and based on construction costs for similar projects in the Bellingham area
Reining in the Rain, City of Bellingham, WA 2004
EPA Study: Reducing Stormwater Costs through Low Impact
Development Strategies and Practices
Background on LID
Discussion of benefits and costs
Case studies 17 projects
LID costs vs. traditional stormwater management on a site or neighborhood scale
Key Findings
In most cases LID
designs showed
cost savings over
traditional
stormwater designs
Capital cost
savings ranged
from 15% to 80%
Other Economic Benefits • The New Kensington Community Development
Corporation and the Pennsylvania Horticultural Society implemented green retrofit measures in a community area in Philadelphia
• NKCDC and PHS converted unsightly abandoned lots with “clean & green” landscapes of mowed grass, ringed with trees
• Significant economic impacts from these green retrofits: Vacant land improvements resulted in surrounding
housing values increased by as much as 30% New tree plantings increased surrounding housing
values by approximately 10% • This translated to a $4 million gain in property values
through tree plantings and a $12 million gain through lot improvements University of Pennsylvania
Up Next
The Role of Codes and
Ordinances in Water Quality and
Non-Point Source Reduction
Juli Beth Hinds
Tetra Tech, Inc.
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